Maxwell Smart: Oh great, I have gum on the bottom of my new shoes. Guy on the plane: Hey! He's trying to light his shoe! Guy on the plane: It's a shoe bomb! Get HIM! Maxwell Smart: No, it's gum. Lady on the plane: Gun? Lady on the plane: He's got a gun! Maxwell Smart: No... GUUUMM! Air Marshal: Air Marshal! You're under arrest! Maxwell Smart: Sir, I believe you just shattered my coccyx!
Max is trying to scrape some gum off the bottom of his shoe using a match while on the plane. His actions are clearly misinterpreted.